Bug 32380 – [Qt] opening a select combo causes crash afterwards

• Component: WebKit Qt
• Status: RESOLVED INVALID

Created attachment 44617 [details]
test example and the test html file

Open a simple webpage with select combo box, if you don't open the drop down list, it works fine. But after opening the select list, when you quits the application, it crashes.
An error message is printed out:
QWidget: Must construct a QApplication before a QPaintDevice
Aborted

And backtrace:
(gdb) bt
#0  0xffffe430 in __kernel_vsyscall ()
#1  0xb5a28990 in raise () from /lib/libc.so.6
#2  0xb5a2a2c8 in abort () from /lib/libc.so.6
#3  0xb5d244fd in qt_message_output (msgType=QtFatalMsg, buf=0x808fd68 "QWidget: Must construct a QApplication before a QPaintDevice")
    at /home/baijing/depot/qt/qt-4.6/src/corelib/global/qglobal.cpp:2226
#4  0xb5d246be in qt_message (msgType=QtFatalMsg, msg=0xb68faacc "QWidget: Must construct a QApplication before a QPaintDevice", ap=0xbfffe184 "\001\006\004")
    at /home/baijing/depot/qt/qt-4.6/src/corelib/global/qglobal.cpp:2272
#5  0xb5d247d9 in qFatal (msg=0xb68faacc "QWidget: Must construct a QApplication before a QPaintDevice") at /home/baijing/depot/qt/qt-4.6/src/corelib/global/qglobal.cpp:2455
#6  0xb62226b6 in QWidgetPrivate (this=0x80e2620, version=263681) at .../qt-4.6/src/gui/kernel/qwidget.cpp:209
#7  0xb6275cea in QDesktopWidgetPrivate (this=0x80e2620) at .../qt-4.6/src/gui/kernel/qdesktopwidget_x11.cpp:106
#8  0xb6275d7a in QDesktopWidget (this=0x80af8e8) at .../qt-4.6/src/gui/kernel/qdesktopwidget_x11.cpp:220
#9  0xb61cff03 in QApplication::desktop () at ...qt-4.6/src/gui/kernel/qapplication.cpp:3064
#10 0xb61cff4f in QApplication::fontMetrics () at .../qt/qt-4.6/src/gui/kernel/qapplication.cpp:2162
#11 0xb76a6615 in ?? () from /usr/local/Trolltech/Qt-4.6.1/lib/libQtWebKit.so.4
#12 0xb76189a3 in ?? () from /usr/local/Trolltech/Qt-4.6.1/lib/libQtWebKit.so.4
#13 0xb75d724b in ?? () from /usr/local/Trolltech/Qt-4.6.1/lib/libQtWebKit.so.4
#14 0xb75dd9ab in ?? () from /usr/local/Trolltech/Qt-4.6.1/lib/libQtWebKit.so.4
#15 0xb75e14d4 in ?? () from /usr/local/Trolltech/Qt-4.6.1/lib/libQtWebKit.so.4
#16 0xb75f428e in ?? () from /usr/local/Trolltech/Qt-4.6.1/lib/libQtWebKit.so.4
#17 0xb75bbce8 in ?? () from /usr/local/Trolltech/Qt-4.6.1/lib/libQtWebKit.so.4
#18 0xb75d546b in ?? () from /usr/local/Trolltech/Qt-4.6.1/lib/libQtWebKit.so.4
#19 0xb75cc597 in ?? () from /usr/local/Trolltech/Qt-4.6.1/lib/libQtWebKit.so.4
#20 0xb75bbce8 in ?? () from /usr/local/Trolltech/Qt-4.6.1/lib/libQtWebKit.so.4
#21 0xb75caab3 in ?? () from /usr/local/Trolltech/Qt-4.6.1/lib/libQtWebKit.so.4
#22 0xb75cc209 in ?? () from /usr/local/Trolltech/Qt-4.6.1/lib/libQtWebKit.so.4
#23 0xb75cc9fa in ?? () from /usr/local/Trolltech/Qt-4.6.1/lib/libQtWebKit.so.4
#24 0xb75bbce8 in ?? () from /usr/local/Trolltech/Qt-4.6.1/lib/libQtWebKit.so.4
#25 0xb75caab3 in ?? () from /usr/local/Trolltech/Qt-4.6.1/lib/libQtWebKit.so.4
#26 0xb75cc209 in ?? () from /usr/local/Trolltech/Qt-4.6.1/lib/libQtWebKit.so.4
#27 0xb75cc9fa in ?? () from /usr/local/Trolltech/Qt-4.6.1/lib/libQtWebKit.so.4
#28 0xb75bbce8 in ?? () from /usr/local/Trolltech/Qt-4.6.1/lib/libQtWebKit.so.4
#29 0xb75caab3 in ?? () from /usr/local/Trolltech/Qt-4.6.1/lib/libQtWebKit.so.4
#30 0xb75cc209 in ?? () from /usr/local/Trolltech/Qt-4.6.1/lib/libQtWebKit.so.4
#31 0xb75cc9fa in ?? () from /usr/local/Trolltech/Qt-4.6.1/lib/libQtWebKit.so.4
#32 0xb75bbce8 in ?? () from /usr/local/Trolltech/Qt-4.6.1/lib/libQtWebKit.so.4
#33 0xb76512b7 in ?? () from /usr/local/Trolltech/Qt-4.6.1/lib/libQtWebKit.so.4
#34 0xb7530aee in ?? () from /usr/local/Trolltech/Qt-4.6.1/lib/libQtWebKit.so.4
#35 0xb752b381 in ?? () from /usr/local/Trolltech/Qt-4.6.1/lib/libQtWebKit.so.4
#36 0xb7592edd in ?? () from /usr/local/Trolltech/Qt-4.6.1/lib/libQtWebKit.so.4
#37 0xb7592f42 in ?? () from /usr/local/Trolltech/Qt-4.6.1/lib/libQtWebKit.so.4
#38 0xb76ab453 in ?? () from /usr/local/Trolltech/Qt-4.6.1/lib/libQtWebKit.so.4
#39 0xb5e40f8f in QObjectPrivate::deleteChildren (this=0x804eb30) at ...qt-4.6/src/corelib/kernel/qobject.cpp:1977
#40 0xb5e480e9 in ~QObject (this=0xbffff0b8) at ...qt-4.6/src/corelib/kernel/qobject.cpp:974
#41 0xb5e342ca in ~QCoreApplication (this=0xbffff0b8) at ...qt-4.6/src/corelib/kernel/qcoreapplication.cpp:620
#42 0xb61db69c in ~QApplication (this=0xbffff0b8) at ...qt-4.6/src/gui/kernel/qapplication.cpp:1113
#43 0x08048d1d in main (argc=Cannot access memory at address 0x8f1
) at main.cpp:18

[Benjamin Poulain]

The code seems invalid. The widget outlive the application.

Try with this:

#include<QApplication>
#include<QWebView>
#include<QUrl>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    QWebView view;
    view.load(QUrl("test.html"));
    view.show();
    return a.exec();
}


For testing Webkit, I suggest using QtLauncher with the html file. That way you don't have to write the code to instantiate a web view.